It is generally accepted that levels of serum whole complement activity(CH50) reflect the activities of complement(C) components of the classical C pathway(CP), since CH50 is assayed by use of sensitized sheep erythrocytes(EA). However, the alternative C pathway(AP) is considered to be also activated simultaneously in the process of activation of serum CP by EA. Thus, serum CH50 levels may possibly reflect not only CP but also AP activation in CH50 assay.
We studied on the influence of AP activation during CH50 assay on CH50
levels, by comparison of CH50 levels in serum samples before and after
treatment of factor D depletion. Polystyrene beads carrying polyanion,
poly(2-acrylamide 2-methylpropane sulfonate)(PAMPS-beads), on the surface
were prepared and used for preparation for factor D-depleted serum. After
treatment of pooled normal human serum (NHS) with PAMPS-beads(2.5 mg/ml
of serum), serum ACH50 level decreased to be undetectable, indicating that
AP activation is prohibited in PAMPS-beads-treated serum. When isolated
factor D was added to this PAMPS-beads-treated serum, ACH50 level recovered
to that of before treatment. Immunoblot analysis revealed that factor D
band observed in NHS disappeared completely after PAMPS-beads treatment.
From these results, it is clear that factor-D deficient serum is prepared
by PAMPS-beads treatment. Besides, since serum CH50 level was not decreased
by PAMPS-beads treatment, it may be concluded that CH50 level is not affected
by AP activation during CH50 assay.
[Rinsho Byori 50 : 815～819, 2002]
*1Department of Clinical Laboratory Science, Osaka Prefecture College of Health Sciences, Habikino 583-8555
【Key Words】CH50，complement activation(補体活性化)，factor D deficient serum(D 因子欠損血清)，alternative pathway(補体第 2 経路)
受付2002年3月29日・受理2002年7月11日
*1,2,4大阪府立看護大学医療技術短期大学部臨床検査学科(〒583-8555 羽曳野市はびきの3-7-30)
*3藤田保健衛生大学医学部微生物学教室(〒470-1192 豊明市沓掛町田楽ヶ窪1-98)